These hints apply to ThumbsPlus version 9 SP1. Most of them apply to earlier versions as well. You can access the hints by symptom or by category. Or just read them all; each will provide some insight into how ThumbsPlus works.

Assuming you have a relatively new CPU (ca. 2009 or newer) and the appropriate amount of RAM for your workload (generally at least 2GB), an SSD is likely the best way to obtain immediate performance improvement for your system in general and ThumbPlus in particular.

I recommend modern SSDs (from 2012 or later), as many of the earlier SSDs had poor write performance, limited lifetime, and rapid performance degradation with a heavy disk write volume. Make sure the SSD you purchase has wear-leveling and implements TRIM. I've bought most of mine from newegg.com. Read the reviews to find the best value.

Here are some hints for the best utilization of SSDs:

Make the SSD your Windows boot disk for immediate performance improvements in booting, starting programs, disk accesses, database accesses, and just about everything you do.

Even if you are accessing the thumbnail database over a network connection (whether the built-in .tpdb8 or client/server), you'll see improvement from an SSD as long as your network is relatively fast and not oversaturated.

For client/server databases with full recovery logging, you'll get the most improvement by placing the database itself on SSD. The log file should be on a separate disk, but it can be on a fast HD since it is written sequentially. It's best to preallocate the full log file size to avoid repeated log file extending and fragmenting.

For client/server database with simple logging, both the log and database can be on the same SSD because simple logging does not use the log the same way as full recovery logging.. See the Client/Server Databases page for additional information about logging and recovery models.

Large images and movies can remain on HD. Sequential access to large files is not improved as much by using an SSD, because disk seeking is much lest frequent. Be sure to defragment your hard disks regularly!

ThumbsPlus itself does not
require a lot of memory, but working with large images does!
If you're working with very large images and are running
other memory-intensive applications, it may take much longer
than expected to view, thumbnail or convert images. Memory
is cheap these days; one of the fastest ways to speed up
your computer is to add memory!

Running a lot of background tasks can require
a lot of memory, especially if large files are being loading.
Try reducing the Maximum concurrent tasks
in Options · Preferences · Advanced.
See Multithreading for more information on
tasks.

For editing images, you can turn off Undo,
or decrease the maximum memory ThumbsPlus will allocate
for Undo operations. Both options are on the Options · Viewing · Editing.

Other programs running
using the CPU ("spinning") can interfere with
ThumbsPlus and other programs. Because any background tasks,
like making thumbnails, run at low priority, it may take
them significantly longer to run. You can enable the option
Run background threads at normal priority
in Options · Preferences · Advanced.
You may also want to use the Windows Task Manager or the
wonderful Process
Explorer from Microsoft to check for other programs
using all of your CPU time.

It can make expanding folders slow because of searching
for sub-folders (in order to display the [+]
for folders with child folders). To speed up the tree,
disableTree · Show Expandable.

It may take a long to to update the file list when
files are change , added or removed from the folder.
To fix this, disable Watch changes in folder
in Options · Preferences · Thumbnail View. With this disabled, you will
need to use Window · Refresh Thumbnails
to see any changes that have occurred in
the folder.

When viewing large numbers of files, the thumbnail
view operates quickest if no user-defined fields are
displayed, and no database information is required
for sorting.

When viewing a single image, ThumbsPlus builds a list
of files for the Previous File and
Next File functions. This can require
a significant amount of memory for tens of thousands
of files.

Occasionally, old TWAIN
drivers can cause ThumbsPlus to be very slow starting up
or hang it altogether. Be sure to uninstall drivers for
any scanners or cameras no longer on your system, and be
sure your drivers are up-to-date for your currently connected
hardware.

If the manufacturer did not provide an easy way (such
as Add/Remove Programs in Control
Panel), you can disable drivers individually
using Device Manager from Control
Panel · Administrative Tools · Computer Management.

If you don't use ThumbsPlus for scanning images, you
can completely disable TWAIN in Options · Preferences · Startup.

If
you're unable to run ThumbsPlus at all (it hangs completely),
you can disable TWAIN by adding -notwain
to the command line for the shortcut. See the screen shot to the right.

Because of the amount
of processing required to completely decode raw camera files,
they are generally slower than other formats. If you need
to rapidly look at a bunch of images, you can use Options · File Plug-ins · Digicam Plug-in to
load the embedded JPEG for viewing. You'll have to change
this back for editing (though batch processing always uses
the full raw image). Also be sure to set your camera for
the largest allowed preview.

If you spend a lot of time culling or sorting raw images,
you can use the slide show as well. By default, the slide
show uses the preview.

Loading some Canon raw (CRW, CR2) files is somewhat faster
if Suppress noise filter is checked on
the Canon tab.

Nikon (NEF) files will generally load faster if you uncheck
Use Nikon libraries to load images on
the Nikon tab.

The default database format
(MS Access JET) is not designed for concurrent use by a
large number of users, so you may see performance degradation
as additional people connect. There is not a specific number
of users — it really depends on how active the users
are and how many are accessing the database simultaneously.

In situations where Access JET is just too slow, we recommend
a client/server database, such as PostgreSQL, MySQL, DB2, or SQL Server. Our database
page lists the databases that we test and support. Also see the Network performance hint below.

ThumbsPlus is database
driven; all thumbnails, annotations, keywords, file information,
galleries and queries are stored in the database. If the
database becomes corrupted because of disk problems or frequent
crashes, or becomes fragmented because of disk fragmentation,
things can become unbearably slow.

Databases upgraded from older versions of ThumbsPlus
may also have thumbnails stored in non-JPEG formats, which
take more disk space and longer to load (with old slow
processors, this was better because the JPEG decompression
was not fast enough for a screen full of thumbnails).

The following steps are for MS Access JET databases only
(.tpdb8, .td4, or .mdb):

Exit ThumbsPlus. If sharing a database, make sure all users have close ThumbsPlus.

Make a backup copy of the database.

Repair the database. File · Database · Repair. This will fix internal errors
in the database.

Compact the database using File · Database · Compact. This is kind of like an
internal defragmentation of the database, and additonally frees
any unused space.

Defragment the disk containing the database. You
should defragment hard disks (HDs) regularly and automatically
for best system performance. I use Raxco's
PerfectDisk, and recommend
it highly. For the most part, you do not need to defragment SSDs, although you may see a small improvement for extremely fragmented files.

Be sure the database is not stored as a compressed file! The
thumbnails themselves, which make up the bulk of the
database, don't compress well anyway, and Windows
compression just adds extra overhead to every
disk operation.

Very rarely, usually after corruption and
repair, Microsoft JET will completely remove an index from
the database. (Indexes are used to quickly locate information).
This can cause excruciating slowness, especially with large
databases. We don't currently have a quick fix to this,
but we plan to build in a check during database repair in
the future.

ThumbsPlus has been multi-processor
compatible and multi-threaded for over 15 years! Any background
tasks (making thumbnails, batch processing, catalogs, contact
sheets, web wizard) run in separate threads that can use
multiple processors. You can see each task on the Tasks
tab. Tasks waiting for an open slot show an hourglass; running
tasks a green arrow. You can set the maximum number of concurrent
tasks in Options · Preferences · Advanced.

When dealing with large images, it's probably
not a good idea to run a lot of background threads, because
of memory limitations on a 32-bit platform. (We're working
on a 64-bit version that will be able to use much more than
the current 4GB limit for 32-bit processes).

Multiple threads are also used for movie
playback, database activities and the preview window. interface.

Since version 7 SP1, image filtering in
a view window uses all processors and cores. Other image
processing functions will be multi-threaded in future releases.

Large thumbnails and annotations require more network bandwidth than smaller ones. Storing all metadata (XMP) in the database can also require more bandwidth. You control this option at Options · Preferences · Thumbnails - Store complete XMP data in database.

These will affect performance more noticeably over a relatively slow connection (< ~100mpbs).

This holds for the built-in Access JET format database (.tpdb8) and all other types of database (see client/server databases). The default database format is designed for sharing by only a few users. See the shared database hint for more information.

Do not put your temporary folder (environment variable TEMP) on a network or external drive. You set its location in Control
Panel · System · Advanced system settings · Advanced · Environment Variables. Set the user variable for TEMP to a local hard drive or SSD. Here is a screen shot from Windows 8.

Don't install ThumbsPlus on a network or external drive. If you share ThumbsPlus between multiple users, it is best to install it locally on each user's system, on either a hard drive or SSD.